W3C home > Mailing lists > Public > w3c-dist-auth@w3.org > April to June 1997

Preliminary Memphis minutes

From: Jim Whitehead <ejw@rome.ICS.UCI.EDU>
Date: Wed, 23 Apr 1997 16:08:50 -0700
To: w3c-dist-auth@w3.org
Message-ID: <9704231608.aa06772@paris.ics.uci.edu>

My apologies for not generating these minutes earlier.  Unfortunately,
I need to submit these minutes on Friday, so please submit any
comments you may have to me by noon Friday.  I'll accept comments
after this time, but they won't be relfected in the minutes published
in the IETF meeting proceedings.  Final call for comments is Friday,
May 2.

I'm particularly interested in people's recollections of issues which
were raised during my slide presentation on locking, metadata,
versioning, and partial write, since my memory is not good on issues
which were raised -- I seem to recall most questions were clarifying
in nature.

These minutes are online, at:



- Jim


Minutes for WEBDAV WG Meeting at Memphis IETF

Preliminary draft, v0.1, April 23, 1997

The WEBDAV Working Group held a meeting at the 38th IETF, in Memphis, TN, on
April 7, 1997. There were approximately 50 people in attendance throughout
the duration of the meeting. The meeting was chaired by Jim Whitehead, and
minutes were collected by Del Jensen. These minutes are reported by Jim
Whitehead due to the unavailability of Del Jensen for medical reasons.

The meeting began with a poll of the audience to determine how many people
in attendance were familiar with the WEBDAV WG. Since approximately on third
of those in attendance were being exposed to WEBDAV for the first time, the
session began with a brief overview presentation on WEBDAV. This
presentation was followed by a discussion, led by Judith Slein, on open
issues in the requirements document.

During these first two presentations, questions were asked about the scope
of the WG's activities with respect to security, authentication, and access
control. The stated response, that WEBDAV was planning on using existing
security and authentication schemes, but was not planning on implementing
new schemes specifically for WEBDAV, met with some scepticism. Several
parties expressed the opinion that distributed authoring in absence of good
security, authentication, and access control was potentially dangerous,
creating a hackers paradise. Another participant stated that expressing the
WEBDAV requirements for security, authentication and access control was a
necessary first step, even if the WEBDAV WG does end up using existing
schemes for this functionality. One participant urged caution when
considering these issues, stating that they were very complex (a.k.a. "pits
of infinite depth"), while another viewed authentication and access control
as server configuration issues, and hence out of scope for the WG. At the
end of the discussion, Judith Slein took an action item to bring up a thread
on the discussion about security, authentication, and access control.

Jim Whitehead next gave a presentation of several topics and preliminary
proposals for their implementation, which were discussed in the Design Team
meeting of April 1-4, 1997, held at U.C. Irvine, specifically locking,
metadata, versioning, and partial write. Discussion of locking centered on a
description of the characteristics of a proposed lock method, which can be
used to provide two types of lock semantics: an exclusive write lock, where
only the principal who owns the lock may modify the state of the resource
(body and metadata), and a shared write lock, where only the principal(s)
who own/share the lock may modify the state of the resource. There was some
discussion about whether it should be possible to lock a deleted or
non-existent resource in order to avoid a race condition between creating a
resource (reserving its name) and then taking out a lock on the resource.
This led to the need to define a new requirement to make it possible to
reserve a name in the namespace controlled by a server.

Also discussed during locking was whether the proposed locking interface was
sufficient for specifying a lock for replicated systems which employ a
golden copy replication system. While no counter examples were found by the
participants, one asked about non-golden copy systems. This raised the issue
of whether locking capability should be a SHOULD requirement, rather than a
MUST requirement, since non-golden copy replicated storage systems cannot
implement a lock as defined.

Metadata facilities were described in terms of a "mixed" model, where small
chunk metadata is expressed using attribute-value pairs stored with a
resource, using new methods GETMETA, PUTMETA, DELMETA, and large chunk
metadata is expressed using a link on the described resource which points to
another resource which contains the metadata description. Referential
integrity can be assured for small chunk metadata, but cannot be assured in
the general case for large chunk metadata.

A proposal for versioning was introduced where instead of using special
checkout and checkin methods, versioning would be performed using the lock,
unlock, and a new "save" method which would update the predecessor and
successor relationships and store an updated resource. A poll of
participants found that they did not understand the new proposal well enough
to tell whether it would work.

The old patch method was resuurected in the proposal for partial write
capability which was presented. The notion of patch is that the body of the
method request contains instructions for how to update the resource
specified by the request URI. It was recommended that multipart/byte-ranges
be used as the default update instruction format which must be supported in
the patch method is supported. This choice was viewed as strange by some
participants. Other update formats suggested were VTML and Unix diff.

*** End of meeting ***
Received on Wednesday, 23 April 1997 19:18:26 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 20:01:10 UTC